1. Field of the Invention
This invention relates to a touch sensor device, a control method, a touch panel device, and a program.
2. Description of the Related Art
In recent years, touch panels used in various industrial equipment use touch sensors which detect which part of the touch panel a human has touched or contacted. When the human touches or contacts an electrode on the touch panel, the same state as a state in which a capacitor having electrostatic capacity equivalent to that of the human body is connected to the electrode is achieved. Utilizing this phenomenon, the touch sensor detects a change in electrostatic capacity formed between this electrode and ground (earth) as an electrical signal.
In this case, the presence or absence of contact is judged by whether the electrical signal detected has a voltage higher than a threshold value or not. However, this threshold value changes according to the temperature or humidity in the surroundings of the touch sensor. If the threshold value is fixed, therefore, the electrical signal may exceed the threshold value because of a temperature change even in the absence of human contact, thereby resulting in a judgment that there has been contact. Even in the presence of human contact, the electrical signal may be unable to exceed the threshold value, and a judgment may be made that there has been no contact.
To solve such problems, it has been known to provide a touch sensor device with a temperature change detecting means and, when a temperature change is detected, correct a threshold voltage according to this temperature change (see, for example, Patent Document 1).    [Patent Document 1] JP-A-08-22361 (see claim 1 and FIG. 2)